JPH0379801A - Positioning actuator - Google Patents

Abstract

PURPOSE:To position a spool and so forth correctly without any effect by a secular change by installing a cylinder mechanism provided with a piston rod expandable according to the volume change in a container, the volume modification member of the container and the volume change of the container. CONSTITUTION:A positioning actuator is provided with a container 1 where hydraulic oil S is sealed, a volume modification rod 2 where the volume of the container 1 can be changed and a cylinder mechanism 5 equipped with a piston rod 8 which is expandable according to the volume change of the container 1 and is connected in serial to the inside of the container 1. With such a means, the protrusion amount of the piston rod 8 can be determined in multiple stages and correctly according to the volume change in the container 1. When the positioning operation of an object to be controlled such as the spool of a proportional solenoid flow control valve is controlled, for example, it is difficult to change the position of the piston rod 8 even if the traveling resistance of the object to be controlled varies with a secular change or fluid power working upon the object to be controlled varies, thus positioning the object to be controlled can stably be made at a prescribed multi-stage position.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field 1] The present invention relates to a positioning actuator for positioning, for example, a spool of a proportional electromagnetic flow control valve at a predetermined position.

[Prior art] Conventionally, for example, in a ratio-1 solenoid: At full control valve,
The flow rate is controlled by adjusting the position of the spool. In this case, the spool has a biasing force of a spring to maintain the spool in a neutral position and a biasing force of a spring to counteract this biasing force. The position is determined by the balance with the applied hydraulic oil pressure.

Therefore, in the case of the proportional electromagnetic flow control valve described above, the position of the spool changes depending on the supplied pressure, thereby controlling the flow rate.

[Problems to be Solved by the Invention] However, with the technology for positioning the spool as described above, the movement resistance of the spool may change due to aging of the pool, deterioration of the hydraulic oil, etc., or the fluid force acting on the spool may change. This has the drawback that the balance of forces applied to the spool changes due to the change in the spool, which also changes the position of the spool.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a positioning actuator that can accurately position a spool or the like without being affected by aging or the like.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a container in which a fluid is sealed, a volume changing member provided in the container and capable of changing the volume of the container, and a volume changer in the volume 2x. and a cylinder mechanism having a piston rod that extends and contracts based on changes in the volume of the container.

[Operation: In the present invention, when the volume of the container is reduced by the volume changing member, the fluid moves toward the cylinder mechanism and the amount of protrusion of the piston rod increases. Furthermore, when the volume of the container is increased, fluid moves from the cylinder mechanism side to the punishment side, and the amount of protrusion of the piston rod decreases.

Therefore, by controlling the volume of the container using the volume changing member, the amount of protrusion of the piston rod can be accurately controlled.

The amount of protrusion of the piston rod is determined by the change in volume of the container, so when controlling the position of a controlled object, such as a spool, with the piston port, the movement resistance of the controlled object may change due to aging. Even if the fluid force applied to the controlled object changes, the position of the piston rod does not change, making it possible to stably hold the controlled object at a predetermined position.

[Example] Hereinafter, the present invention will be described in detail with reference to FIGS. 1 to 6.

First, a first embodiment of the present invention will be described with reference to FIGS. 1 and 2.

In these figures: 1 is a rectangular cylindrical container in which hydraulic oil (fluid) S is sealed, and the side wall la of this container 1 contains the container. A plurality of cylindrical volume changing rods (volume changing members) 2 having different diameters (eight in the figure) that can be protruded into +g l are provided.

Each volume changing rod 2 is connected to a movable iron core 4 that is attracted by a solenoid 3, and when the solenoid 3 is energized, the container is axially moved by a predetermined dimension. It is supposed to move inward.

Further, a through hole 1c is formed in the axial center of the left end wall 1b of the container l on the left side in the figure, and a cylinder mechanism 5 is fixedly provided on the left side of the left end wall 1b.

The cylinder mechanism 5 includes a cylindrical cylinder tube 6, a piston 7 fitted in the cylinder tube 6, and a cylinder connected to the axis of the piston 7.
The piston rod 8 is provided with a piston rod 8 protruding outward from the left end wall 6a of the left side, and a coil spring 9 provided between the left end wall 6a and the piston 7 and biasing the piston 7 to the right side. Right end wall 6b of cylinder tube 6
A through hole 6c communicating with the through hole 1c of the left end wall 1b of the container l is formed in the container l.

Further, on the right end wall 1d of the container 1, there is an origin adjustment rod 10 that passes through the container l from the right side of the right end wall 1d and comes into contact with the axial center of the piston 7. It is attached via a nut l-1.A hydraulic oil inlet 1e, which can be opened and closed by a blind plug 12, is formed in the right end wall 1d of the container l.

In a positioning actuator that is tg-operated like the one shown in Figure 2, by energizing the solenoid 3 at a predetermined position, the volume changing rod 2 corresponding to the solenoid 3 is protruded into the container 1, thereby changing the volume R. ? The volume in r l decreases. Then, by the amount that the volume has decreased, hydraulic oil S
The piston 7 moves toward the cylinder mechanism 5 side, thereby pushing the piston 7 to the left (advancing), and the piston 0/de 8 is pushed outward. Further, when the power supply to the solenoid 3 is cut off, the piston 7 moves (retreats) to the right side until it comes into contact with the origin SRN lower FIQ due to the biasing force of the coil spring 9, and the pressure of the actuation 7T13 S generated thereby causes the piston 7 to The corresponding volume change lot 2h of the solenoid 3 returns to the original (') position, thereby returning the piston rod 8 to its original position.

In addition, in this example, when each volume changing rod 2 is independently protruded, the diameter is 0.1 mm,
0.21.0, 41.0, 81.1.6mm, 3.2m
m, 6.4. The piston rod 8 is designed to move by the respective widths of mm and 1.2.8 mm. However, it is not necessary to limit the dimensions to the above-mentioned 0.1 mm to 12°8), and it goes without saying that you can design it freely, but it is preferable to design it so that it is twice the 1110th order as described above. is preferred.

Moreover, FIG. 2 shows a state in which the volume changing rods 2 indicated by arrows A, B, and C are projected, and in this case, the volume changing rods 2 indicated by arrow A are used to
Since the piston rod 8 is moved by 3.2 mm by the volume changing rod 2 shown by arrow B and 1281 mm by the volume changing rod 2 shown by arrow C, as a result, the piston rod 8 remains 16. 'It becomes 8ml11.

Moreover, when all the solenoids 3 are energized and all the volume change rods 2 are made to protrude, the protrusion amount of the piston rod 8 is 25.5 mm.

According to the positioning actuator configured as described above, the protrusion ffi L of the piston rod 8 is not maintained by force balance between the spring force and the pressure (or electromagnetic force) of the actuating MJ, but by each volume changing rod. For example, when positioning the spool of a proportional electromagnetic flow control valve, even if the force applied from the spool to the piston rod 8 changes, the spool remains unchanged. It can be held precisely in that position. Furthermore, since the amount of protrusion of the piston rod 8 is determined by changes in the volume inside the container 1, even if the sliding resistance of the spool, piston 7, piston rod 8, volume change rod 2, etc. changes due to aging, etc. The amount of protrusion of the piston rod 8 does not change. Therefore, the repeatability is improved under the influence of disturbance.

In addition, as a method for positioning the spool of the proportional electromagnetic flow control valve, a position sensor for detecting the spool position and a power supply unit for passing current through the coil are installed in the flow control valve, and the flow rate setting voltage is controlled by an external control device. The minor loop type proportional electromagnetic method moves the spool by an amount corresponding to the set voltage and detects the amount of movement with a position sensor.
In the case of this minor-loop type proportional electromagnetic method, it is possible to improve the repetition characteristics, but it has the drawback that the set voltage is affected by disturbances such as noise, and moreover, it requires a highly accurate analog signal as the set voltage signal. However, the drawback is that it is only a control device. In contrast, the positioning actuator of this embodiment turns on the current flowing through the solenoid 3.

By turning it off, the spool position can be set accurately, so there is no influence from the nozzle, and there is an advantage that a highly accurate signal is not required as a setting voltage signal.

Furthermore, as a method for positioning the spool of a proportional electromagnetic flow control valve, is there a stepping motor drive method in which an eccentric cam is rotated by a stepping motor and the spool position is determined by the eccentric cam? After completing each process operation, it is necessary to return to the origin and check the zero point), and a unit to drive the stepping motor is required, which creates multiple felt electrical circuits and makes maintenance difficult. . On the other hand, the positioning actuator of this embodiment turns the current to the solenoid 3 ON and OFF.
Since the spool can be positioned simply by FF, there is no need for a complicated amplifier or driver, the cost of the control device can be reduced, and maintenance is also extremely simple.

In the above embodiment, eight volume changing rods 2 are provided, but it goes without saying that the number may be greater or less than this.

Further, instead of the solenoid 2 and the movable core 4 that move the volume changing rod 2 in and out, a hydraulic or pneumatic cylinder 13 as shown in FIG. 3 may be used. In this case, the expansion and contraction speed of the piston rod 8 can be controlled by controlling the speed at which the volume change rod 2 is moved in and out by the cylinder 13, so it is possible to reduce the impact when positioning the piston rod 8. become.

Furthermore, instead of the solenoid 3 and the movable iron core 4, as shown in FIG. , and a nut member i6 whose one end is connected to the end surface of the volume changing rod 2 may also be used.

In this case, the rotation of the electric motor 14 causes the threaded rod 1 to
5 rotates, and the nut member 16 screwed onto the screw stud 15 moves in the axial direction, thereby causing the volume changing rod 2 to move into the container 1.
It begins to appear inside. In this case as well, since the speed of protrusion and retraction of the volume changing rod 2 can be controlled by the rotational speed of the electric motor 14, it is possible to reduce the impact during positioning.

4 and Friend 1 Next, a second embodiment of the present invention will be described with reference to FIG. However, elements common to those of the first embodiment shown in FIG. 1 are given the same reference numerals, and their explanations will be omitted.

This embodiment differs from the first embodiment shown in FIG. 1 in that a configuration for supplying hydraulic oil into the container l is added.

That is, a pipe 21 communicating with the inside of the container 1 is connected to the right end wall 1d of the container 1, and this pipe 2I is connected to a check valve 22 and a pressure reducing valve provided upstream of the check valve 22. It is connected to hydraulic pressure #24 via 23.

The check valve 22 is provided in a direction that allows the flow of hydraulic oil from the hydraulic pressure #24 side to the container 1 side.

The pressure reducing valve 23 is adjusted to a predetermined length by the origin adjustment rod IO (so that the force F2 of the actuation nJIS pushing the piston 7 to the left is smaller than the force F1 of the coil spring 9 in the suspended state). , the set pressure has been adjusted by 1.

In the positioning actuator configured as described above, even if the hydraulic oil S in the container 1 leaks, the M3 pressure i! 1ii24 through the pressure reducing valve 23 and check valve 22. Also, the volume changing rod 2 is retracted and the container 1
When the volume inside the container 1 is changed, the hydraulic oil S in the container 1
is stopped by the check valve 23. Therefore, the piston 7 moves accurately by an amount corresponding to the amount of change in the volume inside the container 1.

According to the positioning actuator configured as described above, even if the hydraulic oil S leaks from the sliding part of the volume changing rod 2 or the sliding part of the piston 8, the leaked part of the hydraulic oil S is absorbed from the hydraulic pressure #24. Since the piston rod 8 is captured, the amount of protrusion of the piston rod 8 can always be accurately controlled by the protrusion and retraction of each volume changing rod 2.

In other respects, the same effects as in the first embodiment are achieved.

Spoon master! ,,! ! U A third embodiment of the present invention will be described with reference to FIG. However, elements common to those of the second embodiment shown in FIG. 5 are given the same reference numerals and their explanations will be omitted.

This embodiment differs from the second embodiment shown in FIG. It's different.

That is, the piping 25 has one end connected to the left end wall tb of the container 1.
The other end is connected to the right end L"6b of the cylinder tube 6, and the piston 7
(the ring piston rod 8 side of the piston 7).

Further, an origin adjustment port 26 is inserted into the right end wall 6b of the cylinder tube 6, and extends from the right side of the right end wall 6b to a position where it abuts the piston 7 in the cylinder tube 6. The axial position of the origin adjustment rod 26 is adjusted by an origin adjustment nut 27 provided on the right end wall 6b.

The positioning actuator configured as in -E has the advantage of being able to position, for example, a spool, etc. at a location away from the container 1.

In other respects, the same effects as in the second embodiment are achieved.

In the above embodiment, the piston rod 8 is used to control the positioning of the spool of a proportional electromagnetic control valve as a controlled object, but the present invention is not limited to the positioning control of the spool, It can be used to control the displacement and collapse of the spring that biases the poppet of a control valve, and to transport positioning tables and objects.

[Effect of the Invention 1] As explained above, according to the present invention, a container in which a fluid is sealed, a volume changing member provided in the container and capable of changing the volume of the container, and communicating with the inside of the container. , and a cylinder mechanism having a piston rod that expands and contracts based on changes in the volume of the container, so that the protrusion and collapse of the piston rod can be accurately determined in multiple stages based on changes in the volume of the container. Therefore, when positioning and controlling a controlled object such as the spool of a proportional electromagnetic flow control valve using a piston rod, the movement resistance of the controlled object changes due to aging, etc., and the fluid force applied to the controlled object changes. Even if the position of the piston rod changes, the controlled object can be stably positioned at multiple predetermined positions.

In addition, by increasing or decreasing the number of volume changing members, the positioning resolution of the piston rod can be set appropriately, and by changing the diameter and movement stroke of the volume changing members, the moving distance of the piston rod can be set arbitrarily. This has the advantage of being able to arbitrarily obtain positioning characteristics by adapting it to the controlled object.

[Brief explanation of drawings]

1 to 6 are diagrams showing embodiments of the present invention, in which FIG. 1 is a sectional view showing the positioning actuator of the first embodiment, and FIG. 2 is a diagram showing the displacement of the positioning actuator operated. 3 is a sectional view showing an example of a pond in the first embodiment, FIG. 4 is a sectional view showing an example of a pond in the first embodiment, and FIG. 5 is a sectional view showing an example of a pond in the first embodiment. FIG. 6 is a sectional view showing the positioning actuator of the third embodiment. l... Container, 2... Volume changing rod (volume changing member), 5...
...Cylinder mechanism, 8...Piston rod, S...Hydraulic oil (fluid).

Claims (1)

[Claims] A cylinder mechanism including a container in which a fluid is sealed, a volume changing member provided in the container and capable of changing the volume of the container, and a piston rod that communicates with the container and expands and contracts based on changes in the volume of the container. A positioning actuator comprising: